questions about bandgap startup circuit

hi all,
i wanna do some research about the startup circuit of bandgap, please help me
1:how to analysis the numbers of the stable operating points of the circuit. as far as i know, some bandgap circuits have 2 stable operating points, some circuits have 3 stable operating points. I wanna know are there some methods to count the numbers of stable operating points?
2:how to analysis a kind of startup circuit can work properly? what kind of situation can make the bandgap circuit fail to startup?
3:is there any method to calculate the startup time and the overshot time?
any suggestion or any paper reference is highly appreciated.
ps: pls show me the paper download links, thanks all

no one cares?

you can refer this book：Voltage Reference - From Diode To High Precision High Order BandGap， it can be found here。